mirror of
https://github.com/bolero-MURAKAMI/Sprout
synced 2024-11-12 21:09:01 +00:00
89 lines
3.2 KiB
C++
89 lines
3.2 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2011-2017 Bolero MURAKAMI
|
|
https://github.com/bolero-MURAKAMI/Sprout
|
|
|
|
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
=============================================================================*/
|
|
#ifndef SPROUT_CSTRING_STRSPN_HPP
|
|
#define SPROUT_CSTRING_STRSPN_HPP
|
|
|
|
#include <iterator>
|
|
#include <type_traits>
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/workaround/std/cstddef.hpp>
|
|
#include <sprout/iterator/operation.hpp>
|
|
#include <sprout/tuple/tuple/tuple.hpp>
|
|
#include <sprout/tuple/tuple/get.hpp>
|
|
#include <sprout/type_traits/is_char_type.hpp>
|
|
#include <sprout/cstring/strchr.hpp>
|
|
|
|
namespace sprout {
|
|
namespace detail {
|
|
template<typename InputIterator1, typename ForwardIterator2>
|
|
inline SPROUT_CONSTEXPR sprout::tuples::tuple<InputIterator1, std::size_t, bool>
|
|
strspn_impl_1(
|
|
sprout::tuples::tuple<InputIterator1, std::size_t, bool> const& current,
|
|
ForwardIterator2 first2, typename std::iterator_traits<InputIterator1>::difference_type n
|
|
)
|
|
{
|
|
typedef sprout::tuples::tuple<InputIterator1, std::size_t, bool> type;
|
|
return sprout::tuples::get<2>(current) || !*sprout::tuples::get<0>(current) ? current
|
|
: n == 1 ? *sprout::detail::strchr(first2, *sprout::tuples::get<0>(current))
|
|
? type(sprout::next(sprout::tuples::get<0>(current)), sprout::tuples::get<1>(current) + 1, false)
|
|
: type(sprout::tuples::get<0>(current), sprout::tuples::get<1>(current), true)
|
|
: sprout::detail::strspn_impl_1(
|
|
sprout::detail::strspn_impl_1(
|
|
current,
|
|
first2, n / 2
|
|
),
|
|
first2, n - n / 2
|
|
)
|
|
;
|
|
}
|
|
template<typename InputIterator1, typename ForwardIterator2>
|
|
inline SPROUT_CONSTEXPR sprout::tuples::tuple<InputIterator1, std::size_t, bool>
|
|
strspn_impl(
|
|
sprout::tuples::tuple<InputIterator1, std::size_t, bool> const& current,
|
|
ForwardIterator2 first2, typename std::iterator_traits<InputIterator1>::difference_type n
|
|
)
|
|
{
|
|
return sprout::tuples::get<2>(current) || !*sprout::tuples::get<0>(current) ? current
|
|
: sprout::detail::strspn_impl(
|
|
sprout::detail::strspn_impl_1(
|
|
current,
|
|
first2, n
|
|
),
|
|
first2, n * 2
|
|
)
|
|
;
|
|
}
|
|
template<typename InputIterator1, typename ForwardIterator2>
|
|
inline SPROUT_CONSTEXPR std::size_t
|
|
strspn(InputIterator1 first1, ForwardIterator2 first2) {
|
|
typedef sprout::tuples::tuple<InputIterator1, std::size_t, bool> type;
|
|
return sprout::tuples::get<1>(sprout::detail::strspn_impl(type(first1, 0, false), first2, 1));
|
|
}
|
|
} // namespace detail
|
|
|
|
// 7.21.5.6 strspn function
|
|
//
|
|
// recursion depth:
|
|
// O(log(N1+N2))
|
|
//
|
|
inline SPROUT_CONSTEXPR std::size_t
|
|
strspn(char const* s1, char const* s2) {
|
|
return sprout::detail::strspn(s1, s2);
|
|
}
|
|
|
|
template<typename Elem>
|
|
inline SPROUT_CONSTEXPR typename std::enable_if<
|
|
sprout::is_char_type<Elem>::value,
|
|
std::size_t
|
|
>::type
|
|
strspn(Elem* s1, Elem* s2) {
|
|
return sprout::detail::strspn(s1, s2);
|
|
}
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_CSTRING_STRSPN_HPP
|